Steps to the formation of stars and planets:
Animations showing a simulation of much of steps 2-10 can be found here
- Clouds of gas form within galaxies.
- Formation of structure within the gas clouds, due to "turbulence" and activity of new stars.
- Random turbulent processes lead to regions dense enough to collapse under their own weight, in spite of a hostile environment.
- As blob collapses, a disk forms, with growing "protostar" at the center.
- At the same time, bipolar outflows from forming star/disk system begin.
- Material is processed, moving in from the blob to the disk. What is not lost in the outflow builds up on the protostar.
- When the protostar begins to undergo fusion, it becomes a real star.
- Once the outflow ceases and the "accretion" phase that lead to the buildup of the star ends, a disk of "leftover" material is left around the star.
- At or near the end of the
star-formation process, the remaining material in the "circumstellar disk"
(a.k.a. "protoplanetary disk") forms a variety of planets.
- Eventually, all that is left behind is a new star, perhaps some planets, and a disk of left-over ground-up solids, visible as a "Debris Disk" around stars other than the Sun, and known as the "Zodaical Dust Disk" around the Sun.
Note: This site was developed by Alyssa Goodman and her
colleagues to support three efforts.
- Public outreach for the Spitzer Space Telescope mission, in conjunction with a NASA Space Science Update on March 25, 2003.
- A whitepaper describing a planned "Research Briefing" by the National Academy's Committee on Astronomy And Astrophysics on Star and Planet formation.
- Public outreach in support of the COMPLETE Survey of Star-Forming Regions.